Digital Climatic Atlas of Texas - Texas Water Development Board

Digital Climatic Atlas of Texas
Executive Summary
A digital climatic atlas of Texas has been created that defines the climate in terms
of major climatic parameters, precipitation, maximum and minimum temperatures and
lake evaporation. Datasets from wide-ranging sources of varying quality and resolutions
were processed and assembled to create this comprehensive dataset of monthly and
annual decadal means both in gridded (4 km) and point format for 11 decades from 1890
to 2000. The datasets used to develop these gridded and point decadal means went
through a variety of QA/QC procedures, data homogenization and infilling techniques to
create the best possible serially complete data for estimating long-term decadal means.
The accuracy of gridded datasets of precipitation and temperature obtained from the
PRISM database were assessed based on independent sets of observation from the Texas
High Plains ET network. Due to low station density and lack of long-term pan
evaporation data, the aerodynamic method was used to create high resolution lake
evaporation estimates based on the gridded weather parameters obtained from PRISM
and subsequently adjusted based on the point observations. ArcGIS geodatabases
containing gridded data and a database containing point monthly and annual decadal
means of climatic parameters were developed to facilitate efficient transfer and use of
data. Further, using this high resolution spatial data, a schema has been proposed to
classify Texas into climatic zones of varying size by using a statistical procedure. This
high-resolution digital climatic dataset will be of immense use for large scale and local
water resources planning and conservation projects in addition to analysis of extreme
events such as droughts and floods.
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